Dental hygiene therapy workforce density and post-extraction infection readmission in Malawian district hospitals: a multilevel threshold estimation

Malawian district hospitals perform most dental extractions with minimal dental hygiene therapy staffing, yet the relationship between workforce density and infection-related readmission has not been quantified. The framework treats workforce density as a hospital-level exposure, readmission as a patient-level binary outcome, and specifies a random-intercept logistic model with a piecewise-linear threshold term. Using published DHS Program data on household water treatment by solar disinfection from 31 African countries (66 country-survey observations, 2006-2025; mean 0.059, SD 0.12), the paper illustrates the data structure and distributional features that a threshold analysis would need to accommodate. The framework proposes that a workforce density threshold exists below which infection readmission risk rises steeply, and specifies the estimation, identification and sensitivity procedures required to test this proposition. The contribution is methodological: a transferable design for threshold estimation in low-resource dental service settings, with explicit attention to confounding, clustering and outcome definition.